Reaction of both active site thiols of reduced thioredoxin reductase with N-ethylmaleimide.
Reaction of both active site thiols of reduced thioredoxin reductase with N-ethylmaleimide.
复制标题
还原型硫氧还蛋白还原酶的两个活性位点硫醇与 N-乙基马来酰亚胺的反应。
作者：
M. O'Donnell;C. Williams
来自大肠杆菌的硫氧还蛋白还原酶仅在其还原状态下与2摩尔N-乙基马来酰亚胺快速反应，其特异性地烷基化两个活性位点半胱氨酸残基。这种双重修饰支持先前的研究，表明碱基降低了两个活性位点半胱氨酸残基的pK。双重修饰还表明，活性位点二硫醇周围的区域比相关酶硫辛酰胺脱氢酶和谷胱甘肽还原酶的情况更开放，这两种酶都可以仅在一个新生硫醇上烷基化。活性位点硫醇的亲核性增强与硫氧还蛋白还原酶的化学机制一致。给出了氨基末端16个残基的序列。
Thioredoxin reductase from Escherichia coli, only in its reduced state, reacts rapidly with 2 mol of N-ethylmaleimide, which specifically alkylates both active site cysteine residues. This dual modification supports previous studies indicating that a base lowers the pK of both active site cysteine residues. The dual modification also indicates that the region around the active site dithiol is more open than is the case with the related enzymes lipoamide dehydrogenase and glutathione reductase, both of which can be alkylated only on one nascent thiol. Enhanced nucleophilicity of the active site thiols is consistent with the proposed chemical mechanism of thioredoxin reductase. The sequence of the amino-terminal 16 residues is presented.
猪肾D-氨基酸氧化酶的一级结构。
DOI：
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发表时间：
1982
期刊：
The Journal of biological chemistry
影响因子：
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作者：
Swenson,RP;WilliamsJr,CH;Massey,V;Ronchi,S;Minchiotti,L;Galliano,M;Curti,B
通讯作者：
Curti,B